Understanding the nature of immunity following mild/asymptomatic infection with SARS-CoV-2 is crucial to controlling the pandemic. We analyzed T cell and neutralizing antibody responses in 136 healthcare workers (HCW) 16-18 weeks after United Kingdom lockdown, 76 of whom had mild/asymptomatic SARS-CoV-2 infection captured by serial sampling. Neutralizing antibodies (nAb) were present in 89% of previously infected HCW. T cell responses tended to be lower following asymptomatic infection than in those reporting case-definition symptoms of COVID-19, while nAb titers were maintained irrespective of symptoms. T cell and antibody responses were sometimes discordant. Eleven percent lacked nAb and had undetectable T cell responses to spike protein but had T cells reactive with other SARS-CoV-2 antigens. Our findings suggest that the majority of individuals with mild or asymptomatic SARS-CoV-2 infection carry nAb complemented by multispecific T cell responses at 16-18 weeks after mild or asymptomatic SARS-CoV-2 infection.

了解 SARS-CoV-2 轻度/无症状感染后免疫的本质对于控制大流行至关重要。我们分析了英国封锁后 16-18 周 136 名医护人员 (HCW) 的 T 细胞和中和抗体反应，其中 76 名医护人员通过连续采样捕获了轻度/无症状的 SARS-CoV-2 感染。 89% 的先前感染的医护人员体内存在中和抗体 (nAb)。无症状感染后的 T 细胞反应往往低于报告 COVID-19 病例定义症状的人，而无论症状如何，nAb 滴度都保持不变。 T 细胞和抗体反应有时不一致。 11% 缺乏 nAb，并且 T 细胞对刺突蛋白的反应无法检测到，但 T 细胞与其他 SARS-CoV-2 抗原发生反应。我们的研究结果表明，大多数轻度或无症状 SARS-CoV-2 感染者在轻度或无症状 SARS-CoV-2 感染后 16-18 周时携带 nAb，并由多特异性 T 细胞反应补充。